Winchester 9mm Case Split vertically in middle

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Hi,

I was wondering if anyone knows what might be causing this?

These are first time shot 9mm Luger Winchester cases, shooting 140gn lead projectiles at around 860fps through a Sig Sauer P226.

I don't seem to have any issues with case extraction, the ejector print on the cases seem to be in a different location for each case, and there's no visible signs of any damage in the chamber - so at this stage I think I can rule out damage in the chamber.

The brass was gauged after reloading, prior to shooting.

One of the guys at the range reckons it might be a bad batch of cases, but I was wondering if anyone else has seen this before. Most splits I've observed normally occur at the end of the case, not in the middle like this.

Also - do you think this could be causing damage to the gun? Is it safe to shoot off the existing rounds that I have loaded. At this stage I'm seeing around 1 in 30 like this.

[Malamute]

I think its a case failure. I had a similar thing happen with a round of 1920s 30-06 ammo. I stopped shooting it.

I recall this coming up somewhere else online several years ago, I think the conclusion of smart people was a case failure, but I don't recall exactly. Hopefully someone else may have more info.

[OlongJohnson]

Clean your barrel and inspect your chamber. The blast may cut potholes in the chamber wall.

[Lost River]

If you have the ability, I would measure case wall thickness on the opposite side of the crack, in the immediate vicinity of the crack, as well as towards the web, and mouth, and compare.

[Hambo]

I've had that kind of split (not in 9mm) but only after loading them numerous times. The only thing I've had split exactly like that on a first firing was in the neck of brass that had been worked hard to form another caliber. I would either call Winchester and see if they will help you out or just throw out the brass. If 1 of 30 is going on the first loading, the problem will only get worse.

[TiroFijo]

9 mm cases are very strong, and your load is supposed to be mild. There is something wrong, either with the batch of brass or the load.

Apparently you don't have chamber erosion so far (I would not expect any with a few micro split cases), but 1 in 30 is too much, you have to change something.

[Chuck Haggard]

I wouldn't shoot any more of that ammo.


New cases? Once fired? Or?

[psalms144.1]

I wouldn't use that lot of brass anymore, or shoot anymore of the loaded ammunition. I'd forward those photos to WCC and let them tell you what they think - but if that's new, unfired commercial brass, there's something seriously wrong there...

[JohnO]

Don't use it! More info please on the origins of the ammo. Sounds like it may be range reloads?

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Thanks all for your replies...

To answer the questions - this is brand new unprimed brass, straight out of the packet. (Not range reloads)

From the replies, it sounds as though it could damage my chamber, so I won't be shooting anymore from that batch. The problem being, is that I've purchased (and loaded) close to a thousand of these brass. Sounds like it's a costly problem that I'll have to discard all those.

I'll see if I can get a response back from Winchester. Thanks for the replies.